* {
  box-sizing: border-box;
}
body {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  margin: 0;
}
.container {
  display: flex;
  width: 90vw;
}
.panel {
  background-size: cover;
  background-position: center;
  height: 80vh;

  border-radius: 50px;
  color: rgb(209, 49, 49);
  cursor: pointer;
  flex: 0.5;
  margin: 10px;
  position: relative;
  transition: all 1s ease-in;
}
.panel h3 {
  font-size: 24px;
  position: absolute;
  bottom: 20px;
  left: 20px;
  opacity: 0;
}
.panel.active {
  flex: 5;
}
.panel.active h3 {
  opacity: 1;
  transition: opacity 0.3 ease-in 0.5;
}